Method for smelting in reduction period of electric furnace steel making

Abstract

The invention relates to a method for smelting in reduction period of electric furnace steel making, comprising the following steps of: I, melting scrap steel, namely adding full-scrap steel into an electric furnace and electrifying to melt the scrap steel, heating the scrap steel to 1590-1650 DEG C, wherein blast oxygen flow is 1300-1900Nm<3> / min, after the melting period of the electric furnace is finished, adding 2.5-3.5kg of FeSi per ton molten steel, and entering the reduction period; II, mixing while nitrogen is blown, namely closing an oxygen valve and opening a nitrogen valve, wherein the pressure is 0.4-0.6MPa, and blast nitrogen flow is 750-1050Nm<3> / min; when nitrogen blowing is started and the outlet of an oxygen lance is inserted 30-50mm below top of slag, and deeply blowing nitrogen after FeSi to be added is molten, wherein the insertion depth of the oxygen lance is 400-600mm, and the nitrogen pressure is 0.7-0.9Mpa, thus the mass percentage of components of the molten steel can reach the requirement by the blowing; and III, finishing nitrogen blowing, namely pulling the oxygen lance out of the top of the slag after the nitrogen blowing is finished, and closing a nitrogen switch and rotating a furnace door oxygen lance to leave a furnace door. The method for smelting in the reduction period of electric furnace steel making has the advantages that the composition of the molten steel is uniform and slag overflow in the tapping process is obviously reduced.

Description

technical field [0001] The invention relates to a method for smelting in the reduction period of electric furnace steelmaking. Background technique [0002] In the electric furnace link of stainless steel smelting, the dynamic conditions in the furnace are the key factors that limit the reduction time and reduction effect of the electric furnace. In the existing electric furnace steelmaking reduction period smelting method, it is difficult to adjust the dynamic conditions in the furnace during the reduction period, which will lead to uneven temperature and composition in the furnace, resulting in poor reduction effect and Cr in the slag. 2 o 3 The content is high, resulting in serious loss of precious metals, and the composition and temperature of molten steel in the tapping ladle are not uniform (the electric furnace of the applicant's unit is tapped in two ladles). Due to insufficient reduction, there are more dissolved oxygen in molten steel and slag, resulting in the r...

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Problems solved by technology

In the existing electric furnace steelmaking reduction period smelting method, it is difficult to adjust the dynamic conditions in the furnace during the reduction period, which will lead to uneven temperature and composition in the furnace, resulting in poor reduction effect and Cr in the slag. 2 o 3 The content is high, resulting in serious loss of precious metals, and the composition and temperature of molten steel in the tapping ladle are not uniform (the electric furnace of the applicant's unit taps steel in two ladles)

Due to insufficient reduction, there are more dissolved oxygen in molten steel and slag, resulting in the reaction of oxygen dissolved in molten steel and slag with carbon during the tapping process to form CO bubbles, causing molten steel to boil, prolonging the tapping time, and even burning out the equipment in severe cases , affecting normal production

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